Sewing machines attachment for the sewing of resilient workpieces



March 26, 1963 K. NICOLAY sswmc MACHINES ATTACHMENT FOR THE SEWING 0F RESILIENT,,WORKPIECES Filed Nov. 10, 1960 4 Sheets-Sheet 1 INVENTOR:

KARL NlCOLAY m AGENT 3,082,716 SEWING March 26, 1963 K. NICOLAY szwmc MACHINES ATTACHMENT FOR THE OF RESILIENT WORKPIECES 4 Sheets-Sheet 2 Filed Nov. 10, 1960 INVENTOR KARL NICOLAY March 26, 1963 K NICOLAY 3,082,716

SEWING MACHINES ATTACHMENT FOR THE SEWING OF RESILIENT WORKPIECES Filed Nov. 10. 1960 4 Sheets-Sheet s 77 I nvvz-wroR: 62 6 64 63 KAR L N IC OL AY BY wk AGENT March 26, 1963 K. NICOLAY 3,082,716

SEWING MACHINES ATTACHMENT FOR THE SEWING OF RESILIENT WORKPIECES Fild NOV- 10, 1960 4 Sheets-Sheet 4 35 3a 43 56 so 11 5 2% 4 39- f 57 Flg.l0 40' 56 41 I \55 5.9 Q

INVENTOR.

KARL NICOLAY United States Patent Ofifice 3,082,716 Patented Mar. 26, 1963 3,082,716 SEWING MASHENES ATTACHMENT FOR THE SEWHNG 6F REEILIENT WORKPIECES Karl Nicolay, Bieleield, Germany, assignor to Durkoppwerlke Aktiengesellschaft, Bielefeid, Germany, a corporation of Germany Filed Nov. 10, 1960, Ser. No. 68,529 Claims priority, application Germany Nov. 14, 1959 12 Claims. (Cl. 112-2) This invention relates to an attachment for the sewing of resilient materials, for example for the sewing on of resilient inserts for an article of clothing. This attachment is suitable for straight-stitch and zig-zag-stitch sewing machines, and also for sewing machines which in known manner are provided with a combined feed device consisting of a lower material feeder, a needle rod swinging out in the direction of the sewing and a controlled presser also called a hopper foot. The apparatus involves the use of a looper bar co-operating with the needle for the formation of thread loops over the workpiece.

Such looper bars for sewing machines are known. They serve the most varied purposes, for example for making carpets, blankets, fringes or the like, by forming one or more rows of thread loops on a basic material or for the making of button links in the sewing on of buttons with the aid of button-stitching machines. For the last mentioned use, looper bars are already known which, in stationary machines, are adjustable in height in order to make it possible to sew on buttons with links of different length. Furthermore, it is known to make the bar laterally swingable in order to facilitate the sewing on, with the same sewing machine, of buttons with out links.

All these known arrangements are unsuitable for the solution of the problem to which the present invention is directed. The problem consists essentially in providing an attachment for sewing machines which facilitates the sewing on or sewing in of resilient materials, for example wadding or foamed rubber, on or between one or several layers of material in such manner that during the sewing procedure the workpiece, compressed by the presser 'foot in consequence of its resilience, is not held in its compressed state behind the stitching point by firm sewing stitches but can return at least approximately to its original state as regards thickness. This arrangement is for example particularly well suited for the insertion of the sleeves of an article of clothing tightly in the lower part of the arm hole and with looser stitches in the upper part of the armhole where a padding is provided.

A further problem consists in so forming the attachment that resilient materials of difierent normal thickness and dilferent resilience can be worked Without interruption of the stitch-forming operations of the sewing machine. Furthermore, an attachment responding automatically to the thickness and resilience ofthe workpiece is to be provided. Finally, there is still the problem of so forming the attachment that it can be switched on or oil as desired during the sewing, in order to permit carrying out with the machine either the sewing on of resilien't materials onto a workpiece or ordinary sewing work.

The invention solves this problem essentially in that a looper bar used on the sewing machine during the formation of loops is made adjustable in height in relation to the workpiece surface by manually or mechanically controlled transmission members. In this connection, by manually operating transmission members are to be understood hand levers and operating devices in operative connection with the looper bar to be actuated by the fore-arm of the operator, .by pedals or by means of the knee. As mechanically controlled transmission means are to be considered all driving means for the looper bar controlled in dependence on the rotation of the sewing machine, for example by curved plates or cams, and independently of the sewing machine drive.

If the attachment is to be used on a straight stitching machine, then pivoting movements reciprocating in dependence on the needle movement must be imparted to the height-controlled bar.

The height adjustment of the looper bar may be automatically controlled also by means of a feeler member sensing the workpiece in the area of the stitching point of the needle. This feeler member consists of a two armed lever, one arm of which terminates in a sensing finger contacting the workpiece in the vicinity of the stitch point of the needle, and the other arm of which is bent upwards substantially at right angles in order to effect, via a bell-crank lever, the height adjustment of the looper bar. The looper bar itself is fixed to a supporting block, angularly swingable and axially movable on the presser bar, which, for the purpose of the height adjustment of the bar isin working engagement with the bellcrank lever and, via a coupling from an engageable and disengageable transmission, receives angularly pivoting movement for the formation of thread loops by means of the looper bar. For the purpose of fine adjustment of the working height of the bar, the lever in working communication with the feeler member has a pin movable to selected positions in a slot in the bell-crank lever and engaging a groove in the block. The lower arm of the bell-crank lever is likewise provided with a pin movably fixed in a slot which is pressed by means of a further lever, rotatably arranged under the tension of a spring, onto the arm of the two-armed lever.

The coupling for the communication of the pivoting movements to the overedge looper bar from the said transmission consist of a pin, which is inserted in a projection of thesupporting block, and a dog embracing the pin on a part of its periphery, this dog being fixed to a pusher or thrust rod. The two-armed lever with the feeling member and the bell-crank lever are rotatably arranged on a holding plate fixed on the sewing-machine head,

which has an opening for the mounting and guiding of the thrust rod.

The engageable and disengageable transmission for producmg the pivoting movement of the looper bar has a driving cam, rotated via a pair of gear wheels,

and a pivot lever capable of being brought into an ineffective position by means of a decoupling mechanism, and of co-operating with this cam under the action of a spring, to which the thrust rod in linked. The decoupling mechanism consists of a catch swingable on the pivot lever against-the action of ,a spring, a stop bolt co-operating with .this catch and a cam-shaped toggle memberadapted to be brought to bear on the catch by means of a handle in order to hold the pivot lever in an inefiective pos1t1on.

A representative embodiment of the invention is .illustratedin the accompanying drawing, wherein:

FIG. 1 shows the attachment according to the invention on a flat-bed sewing machine, with a combined.

feed arrangement consisting of a lower material feeder, a needle rod swinging out in the direction of the stitching and a controlled work presser all in perspective representation;

FIG. 2 shows in perspective, and drawn to a larger scale, a part of the machine shown in FIG. 1;

FIG. 3 is a side view of the arrangment shown in FIG. 2, with the presser foot lowered;

FIG. 4 shows the same parts as FIG. 3 but with the presser foot raised;

FIG. 5 shows a partial section through the sewing machine, taken on line VV of FIG.17;

FIG. 6 shows a section corresponding to FIG. 5 but with a workpiece inserted; w

FIG. 7 shows a partial view of the attachment as seen from the front;

FIG. 8 is a part-sectional plan view taken on line VIII-VIII of FIG. 7;

FIG. 9 is a partial plan view of the base plate of the sewing machine, showing a coupling transmission with the cover removed; and

FIG. 10 is a sectional elevation through the transmission taken, on line XX of FIG. 9.

' The sewing machine illustrated in FIG. 1 has a base plate 1, a standard or pillar 2 and a cantilever arm 3, terminating in a head 4. The machine also has a combined work-feeding means (FIG. 2) which consists of a lower work feeder 5 and an upper forked work feeder foot 6 having a needle bar 7 with the needle 8 swinging out in the direction of sewing, and a forked presser foot 10, also called a hopper foot, fixed on the presser bar 9.

As can best be seen from FIGS. 5-8, there is located between the two forks 6' and 6" of the upper work-feeder foot 6 a looper bar 11 which can be pivoted to-and-fro sideways under the needle 8 for the formation of thread loops. The bar 11 is fixed to a block 12 by means of screws 13, this block being angularly pivotable and axially movable on the presser bar 9. On its left-hand side (viewed from the front) the block 12 is provided with a groove 14 in which a pin 15 is loosely received, this pin being adjustably fixed in a slot 18 in one arm 16 of a bell-crank lever 16, 17 to enable a more accurate presetting of the swing of bar 11. The lever 16, 17 is rotatably mounted on a stud screw 21 in a holding plate 19 which is fixed to the sewing-machine head 4 by means of screws 20 (FIG. 7). A pin 23 is adjustably inserted in a slot 22 in the arm 17 of the lever 16, 17 and has an annular groove 24 (FIG. 8). A lever 25 and an arm 26 of a double-arm lever 26, 27 are urged towards each other by the tension of a traction spring 28, the ends of which engage said lever 25 and arm 26 respectively. The double-arm lever 26, 27 and the lever 25 are both rotatably mounted on a stud screw 29 on the rear side of the holding plate 19. The arm 27 of the double-arm lever 26, 27 is bent inwards towards the needle 8 and terminates in a sensing finger 30 which is located between the fork 6 of the material-feeder foot 6 and the fork 10' of the presser foot 10.

The block 12 has on its rear side a projection 31 (FIG. 5) in which there is inserted a vertical pin 32, projecting downwards, the upper end of which, on a part of its by a driving shaft 48 located under the base plate 1 for setting in motion a part of the material advancing device and the stitch-forrning tools.

A toggle switch comprising cam 517 is swingably on a bolt 52 in the transmission casing 41. The cam 51 can be pivoted to-and-fro by means of a handle 53 attached to it, this handle projecting through a slot 54 in the front wall of the casing 41. The pawl 43, which is under the action of the spring 44, bears on the cam 51 periphery, is embraced by a dog 33. This dog is fastened by means of screws 34 onto a thrust rod 35 running parallel to the base plate 1, the end of rod 35 adjacent the machine head being movably supported and guided in an opening 36 (FIG. 8) located in the holding plate 19. The other end of the thrust rod 35 nearer the machine pillar 2 (FIG..1) is led to an engageable and disengageable transmission indicated generally at 37 and arranged close to the pillar 2 of the sewing machine on the base plate 1. As can be seen from FIGS. 9 and 10, the opposite end of the thrust rod 35 is linked by means of a stud screw 38 to a pivot lever 39 which is mounted in the transmission casing 41 so as to be rotatable about a bolt 40.

On the pivot lever 39 there is mounted rotatably about a pin 42 a decoupling pawl 43 which is urged in clockwise direction by the tension of a spring 44 whose vertically bent ends abut the pivot lever 39 and the pawl 43. The lever 39 is itself under the traction of the spring 45 which the transmission in its engaged state presses the pivot lever 39 against a control cam 46 fixed on the shaft 47, this shaft being mounted in the transmission casing '41 and passing downwardly through the base plate 1. The shaft 47 is driven via bevel wheels 49'and 50,

which co-operates with a stop bolt 55 which, for this purpose, is formed with a flattened portion 56 and a nose 57 (FIG. 9). A traction spring 58 connected at one end to the casing 41 and at the other end to the cam 51 serves to hold the handle 53 in its position either to the right or to the left of the pivot 52.

The casing 41 is screwed firmly onto the base plate 1 of the sewing machine by means of screws 59 and is covered by means of a lid 60.

The mode of operation of the attachment may be described as follows. As can be seen from FIGS. 2, 3, 5 and 7, the material-presser foot 10 and the materialfeeder foot 6 are located in their lowered positions on the stitching plate of the sewing machine, and the sensing finger 30 and the looper bar 11 are likewise in their lowered position. If after the raising of the presser foot 10 and the feeder foot 6, as shown in FIG. 4, a resilient workpiece (which for example consists of two layers of material 61, 62, with a resilient insert 63, FIG. 6) is introduced into the sewing machine and the presser 10 and feeder 6 are lowered onto the workpiece, then the workpiece is compressed in the vicinity of the sewing point to the mass a, see FIG. 6. The sensing finger 30 now lies likewise on the upper material layer 61, at its depressed level, having been raised from the needle plate by the inserted material. The two-arm lever 26, 27 is thus pivoted around the stud screw 29 to a certain extent in clockwise direction (FIG. 6), and with it also the bellcrank lever 16, 17, is moved about its pivot in clockwise direction and, under the action of the spring 28 bears with its pin 23 against the lever 25 and the arm 26 between which the pin is clamped. This movement of the lever arm 16 has raised the block 12 with the aid of its pin 15 engaging in groove 14 the block 12.

With the raising of the block 12, the bar 11 fixed to it is raised also, and in fact to a height which corresponds approximately to the thickness b (FIG. 6) of the workpiece. If now during the stitching the bar 11 (FIG. 8) is pivoted.to-and-fro stitch by stitch whilst the needle 8 is located above it, then the thread loops 64 are formed over and around the bar 11 and are drawn oi? the bar with the continuous advance of the workpiece, these loops then being filled out behind the stitching point by the resilient workpiece returning to its original form.

The activation of the looper bar 11 from its position of rest indicated in dot and dash lines in FIG. 8 for the receiving of its to-and-fro swinging action under the needle 8 is effected by changing over the handle 53 (FIGS. 1 and 9) to the left into the position shown in dot-and-dash lines in FIG. 9. This action causes pawl 43 under the action of the spring 44, to be disengaged from the nose 57 of the stop bolt 55. Therefore the pivot lever 39, which previously was held out of contact with the cam 46 by the pawl 43, can comes into effective connection with the cam 46 by means of the traction spring 45. The rotations of the driving shaft 48 of the sewing machine effect the rotation of the cam 46 via the bevel wheels 49, 50 and, with the co-operation' of the traction spring 45, a to-and-fro swinging of the pivot lever 39 results. These pivotal movements are transmitted via the thrust rod 35 which is guided into the open ing 36 (FIG. 8) in the holding plate 19'and,.via the coupling connections 33, 3-2, are communicated to the block 12 and thereby also to the bar 11' which can now Upon the complete lifting of the presser foot 10, as in FIG. 4-, not only the material feeder foot 6, but also the sensing finger 30 and'the bar 11 are raised. In this position the double-arm lever 26, 27 carrying the sensing finger 34} is pivoted so far about the stud screw '29 because of the engagement of the presser foot with the arm 27 of that lever, that the arm 26 of the lever is removed from contact with the pin 23 in the bell-crank lever 16, 17, against the tension of spring 28. This lever is limited in its pivotal movement as the pin 15 located in its arm 16 takes along the block 12 to its position of contact with the sewing-machine head 4, in which position also the bar 11 reaches its highest position. The lever 25, rotatably mounted on the pin 29 next to the double-arm lever 26, 27, effects the lifting of the block 12 by the bell-crank lever 16, 17 under the influence of the spring 28.

It will be noted that clamping of pin 23 between lever arms 25 and 26 affords a non-positive, yieldable connection between members 16, 17 and 26, 27 whereby a rise of the feeler member 30 will be communicated to looper bar 11 only to the extent permitted by the loops 64 so that a tearing of the thread or any undue stretching of the loops will be avoided.

The attachment according to the invention is also suitable for sewing machines of other construction, for example upright sewing machines. The sewing machines embodying the inevntion may also be provided with an apparatus for the cutting of the edges of the work-piece, which has been generally indicated at 65 in FIGS. 1 and 2.

What I claim is:

1. A sewing-machine attachment comprising a looper bar spacedly positioned above a work surface, a stationary support holding means for said bar including an elongated member extending from said support substantially perpendicularly to said surface and a mounting longitudinally slidable and angularly swingable on said member, said bar being secured to said mounting, actuating means for periodically swinging said mounting on said member whereby said bar oscillates above said surfaces, a first lever linked with said mounting and pivoted to said support at a first fulcrum, a second lever pivoted to said support at a second fulcrum spaced from said first fulcrum and enagageable at a location adjacent said bar with a workpiece advancing on said surface in a direction transverse to the oscillations of said bar, a motion-transmitting connection between said levers for varying the elevation of said bar above said surface in accordance with the thickness of said workpiece.

2. An attachment acording to claim 1 wherein said actuating means comprises a rotatable cam, link means coupled with said mounting and engageable with said cam, spring means urging said link means into engagement with said cam, decoupling means adapted to maintain said link means spaced from said cam, operating means for inactivating said decoupling means, and drive means for imparting motion to said cam.

3. An attachment acording to claim 2 wherein said link means comprises an elongated rod and a cam-engaging lever articulated to said rod, said decoupling means comprising a fixed stop and a pawl on said cam-engaging lever pivotable into engagement with said stop.

4. An attachment according to claim 3 wherein said operating means comprises a toggle member manually displaceable between a first position disengaged from said pawl and a second position in which said pawl is urged into alignment with said stop by said toggle member, said pawl being provided with resilient means tending to disalign said pawl with said stop.

5. A sewing-machine attachment comprising a looper bar spacedly positioned above a work surface, a stationary support, holding means for said bar including an elongated member extending from said support substantially perpendicularly to said surface and amounting lonsaid surface in accordance with the thickness of said workpiece.

6. A sewing-machine attachment comprising a looper bar spacedly positioned above a work surface, holding means for said bar including an elongated support extending substantially perpendicularly to said surface and a mounting longitudinally slidable on said support, said bar being secured to said mounting, feeler means engageable at a location adjacent said bar with a workpiece advancing on said surface, and a resilient connection between said feeler means and said mounting for tending to vary the elevation of said bar above said surface in accordance with the thickness of said workpiece, said resilient connection comprising a first lever rigid with said feeler means, a second lever coupled with said mounting, an arm pivoted on said first lever, a projection on said second lever received between said first lever and said arm, and spring means interconnecting said first lever and said arm for yieldably clamping said projection therebetween.

7. An attachment according to claim 6 wherein said second lever is provided with a slot, said projection being adjustably fastened to said slot.

8. An attachment according to claim 6 wherein said second lever has a slot and a pin adjustably mounted in said slot, said mounting comprising a block having a groove engaged by said pin.

9. An attachment according to claim 6 wherein said support comprises a post having a presser foot mounted thereon, said first lever having a portion overlying said presser foot for elevating said bar upon a raising of said presser foot from a workpiece positioned between the latter and said surface.

10. A sewing-machine attachment comprising a looper bar spacedly positioned above a work surface, holding means for said bar including an elongated support extending substantially perpendicularly to said surface and a mounting longitudinally slidable and angularly swingable on said support, said bar being secured to said mounting, actuating means for periodically swinging said mounting means on said support whereby said bar oscillates above said surface, feeler means engageable at a location adjacent said bar with a workpiece advancing on said surface in a direction transverse to the oscillations of said bar, and a resilient connection between said feeler means and said mounting for tending to vary the elevation of said bar above said surface in accordance with the thickness of said workpiece, said support comprising a post having a presser foot mounted thereon, said feeler means comprising a bell-crank lever having a first extremity adjacent said presser foot and a second extremity anchored to said resilient connection, said first extremity being engageable by said presser foot for elevating said bar upon a raising of said presser foot from a workpiece positioned between the latter and said surface.

11. A sewing-machine attachment comprising a looper bar spacedly positioned above a work surface, a stationary support, holding means for said bar including an elongated member extending from said support substantially perpendicularly to said surface and a mounting longitudinally slidable on said member, said bar being secured to said mounting, a first bell-crank lever linked with said mounting at one extremity and pivoted to said support at a first fulcrum, a second bell-crank lever pivoted to said support at a second fulcrum spaced from References Cited in the file of this patent UNITED STATES PATENTS Kynaston Dec. 31, 1901 Story et a1 Oct. 30,

Christensen et a1. Oct. 13,

Hickey June 15,

Williams Jan. 13,

Wanzer et a1 Sept. 15,

FOREIGN PATENTS Italy Feb. 28, 

1. A SEWING-MACHINE ATTACHMENT COMPRISING A LOOPER BAR SPACEDLY POSITIONED ABOVE A WORK SURFACE, A STATIONARY SUPPORT HOLDING MEANS FOR SAID BAR INCLUDING AN ELONGATED MEMBER EXTENDING FROM SAID SUPPORT SUBSTANTIALLY PERPENDICULARLY TO SAID SURFACE AND A MOUNTING LONGITUDINALLY SLIDABLE AND ANGULARLY SWINGABLE ON SAID MEMBER, SAID BAR BEING SECURED TO SAID MOUNTING, ACTUATING MEANS FOR PERIODICALLY SWINGING SAID MOUNTING ON SAID MEMBER WHEREBY SAID BAR OSCILLATES ABOVE SAID SURFACES, A FIRST LEVER LINKED WITH SAID MOUNTING AND PIVOTED TO SAID SUPPORT AT A FIRST FULCRUM, A SECOND LEVER PIVOTED TO SAID SUPPORT AT A SECOND FULCRUM SPACED FROM SAID FIRST FULCRUM AND ENGAGEABLE AT A LOCATION ADJACENT SAID BAR WITH A WORKPIECE ADVANCING ON SAID SURFACE IN A DIRECTION TRANSVERSE TO THE OSCILLATIONS OF SAID BAR, A MOTION-TRANSMITTING CONNECTION BETWEEN SAID LEVERS FOR VARYING THE ELEVATION OF SAID BAR ABOVE SAID SURFACE IN ACCORDANCE WITH THE THICKNESS OF SAID WORKPIECE. 